Spiral casing



FIG. 1 is a bottom side of a spiral casing;

FIG. 2 is a front side of a spiral casing;

FIG. 3 is a perspective view of a spiral casing;

FIG. 4 is a rear view of a spiral casing;

FIG. 5 is a side view of a spiral casing;

FIG. 6 is a side view of a spiral casing; and,

FIG. 7 is a top view of a spiral casing.

CLAIM The ornamental design for a spiral casing, as shown and described.